Sprocket arrived last night and followed your instructions and put it on in a jiffy, thanks for that.
The only drama was that I couldn't get the chain guide that sits above the sprocket so sit right without it catching on the chain/teeth of sprocket.
Tried placing a washer behind it to space it out a little as was catching on the face of the sprocket which worked. But still couldn't get it to stop touching the little rubber bit at the back towards the rear cassette.
Even loosened off the 3 little allen bolts that hold the guide in place and tried that in a few different positions but to no avail. In the end just took it off completely, took it for a 15km test ride last night and no dramas at all.
Could feel a little difference in the gearing as in it seemed to pull each gear a bit longer, but didn't do any steep climbs, that'll have to wait for the weekend.
Science says that there is a difference of around 4.5% but I'll never be a TEST DRIVER, just don't seem to notice those little differences.
Got a mate who is the opposite, I reckon if a fly landed on his left grip he would feel it pulling to the left

but unfortunately, that's not me.
Like the way each second tooth on the sprocket is larger to fit into the different sized holes in between the links, very snug fit and probably why you don't need the chain guide.
Will fill you in more after a more hilly ride on the weekend.